Mischa's Friend Comes Out to Play

5/18/2007 5:40 PM PDT

Mischa's Friend Comes Out to Play

There are nip slips -- and then there are full-out boob slips. Mischa Barton gave us the latter.

The former "OC" star was enjoying a night out in London last night, when she returned to her hotel with a male friend. Her top came undone (ya think?!) and gave photogs a little peek before she quickly buttoned up.

Welcome to the club, Mischa.